Note: Consensus and contention percentages are calculated based on the standard deviations of contributor answers.

Participants were asked to apply the ranking factors to Google’s search engine, and although we’ve found that it’s largely applicable to other major US engines (Bing, Yahoo! & Ask), some variance almost certainly exists.

About the Survey

Every two years, Moz surveys top SEO experts in the field worldwide on their opinions of the algorithmic elements that comprise search engine rankings. This year features contributors from the US, UK, Canada, Australia, New Zealand, Iceland, the Ukraine, the Dominican Republic and many more.

Each participant was asked to rate more than 100 search ranking factors along with specific questions about hot issues in the SEO field. This document, representing the collective wisdom of expert practitioners, is, in opinion, one of the most useful resources for SEO practitioners of all varieties, helping to provide transparency into what matters (and doesn’t) for best practices in search engine optimization.

Complete Rankings Data

The following ranking factors were rated by our panel of 72 SEO experts. Their feedback is aggregated and averaged into the percentage scores below. For each, we’ve calculated the degree to which the experts felt this factor was important for achieving high rankings as well as the degree of variance in opinion, estimated using the standard deviation of the contributors’ answers. Thus, factors that are high in importance and low in contention are those where experts agree the most that the factor is critical to rankings.

On-Page (Keyword-Specific) Ranking Factors

Keyword Use Anywhere in the Title Tag

66% very high importance

8% moderate consensus consensus

Keyword Use as the First Word(s) of the Title Tag

63% high importance

11.3% light consensus consensus

Keyword Use in the Root Domain Name (e.g. keyword.com)

60% high importance

11.2% light consensus consensus

Keyword Use Anywhere in the H1 Headline Tag

49% moderate importance

10.2% light consensus consensus

Keyword Use in Internal Link Anchor Text on the Page

47% moderate importance

13% moderate contention consensus

Keyword Use in External Link Anchor Text on the Page

46% moderate importance

13.6% moderate contention consensus

Keyword Use as the First Word(s) in the H1 Tag

45% moderate importance

11.7% light consensus consensus

Keyword Use in the First 50-100 Words in HTML on the Page

45% moderate importance

9.9% light consensus consensus

Keyword Use in the Subdomain Name (e.g. keyword.seomoz.org)

42% low importance

9% light consensus consensus

Keyword Use in the Page Name URL (e.g. seomoz.org/folder/keyword.html)

38% low importance

9.1% light consensus consensus

Keyword Use in the Page Folder URL (e.g. seomoz.org/keyword/page.html)

37% low importance

8.6% light consensus consensus

Keyword Use in other Headline Tags (<h2> – <h6>)

35% low importance

8% light consensus consensus

Keyword Use in Image Alt Text

33% minimal importance

8.7% light consensus consensus

Keyword Use / Number of Repetitions in the HTML Text on the Page

33% minimal importance

10.3% light consensus consensus

Keyword Use in Image Names Included on the Page (e.g. keyword.jpg)

33% minimal importance

8.6% light consensus consensus

Keyword Use in <b> or <strong> Tags

26% minimal importance

7.6% moderate consensus consensus

Keyword Density Formula (# of Keyword Uses ÷ Total # of Terms on the Page)

25% minimal importance

9.8% light consensus consensus

Keyword Use in List Items <li> on the Page

23% very minimal importance

9.5% light consensus consensus

Keyword Use in the Page’s Query Parameters (e.g. seomoz.org/page.html?keyword)

22% very minimal importance

7.6% moderate consensus consensus

Keyword Use in <i> or <em> Tags

21% very minimal importance

8.4% light consensus consensus

Keyword Use in the Meta Description Tag

19% very minimal importance

9.9% light consensus consensus

Keyword Use in the Page’s File Extension (e.g. seomoz.org/page.keyword)

12% very minimal importance

8.3% light consensus consensus

Keyword Use in Comment Tags in the HTML

6% very minimal importance

5.7% moderate consensus consensus

Keyword Use in the Meta Keywords Tag

5% very minimal importance

5.5% moderate consensus consensus

Comments on On-Page (Keyword-Specific) Ranking Factors:

Andy Beal – Keyword use in external link anchor text is one of the top SEO factors overall. I’ve seen sites rank for competitive keywords—without even mentioning the keyword on-page—simply because of external link text.

Andy Beard – Keyword Use in the Meta Keywords Tag – ignore them unless using a blogging platform which can use the same keywords as tags. Google ignores them.

Christine Churchill – Taking the time to create a good title tag has the biggest payoff of any on-page criteria. Just do it!

Duncan Morris – It’s worth pointing out that even though having keywords in the meta description doesn’t impact rankings they can play a significant role in the sites click through rate from the SERPs.

Peter Wailes – Domain name keyword usage gains most of its strength through what anchor text people are then likely to link to you with, not so much from inherent value, which is lower in my opinion.

On-Page (Non-Keyword) Ranking Factors

Existence of Substantive, Unique Content on the Page

65% very high importance

9.2% moderate consensus consensus

Recency (freshness) of Page Creation

50% moderate importance

10.5% moderate consensus consensus

Use of Links on the Page that Point to Other URLs on this Domain

41% low importance

12.6% moderate contention consensus

Historical Content Changes (how often the page content has been updated)

39% low importance

10.9% moderate consensus consensus

Use of External-Pointing Links on the Page

37% low importance

13.3% moderate contention consensus

Query Parameters in the URL vs. Static URL Format

33% minimal importance

11.8% moderate consensus consensus

Ratio of Code to Text in HTML

25% minimal importance

11% moderate consensus consensus

Existence of a Meta Description Tag

22% very minimal importance

11% moderate consensus consensus

HTML Validation to W3C Standards

16% very minimal importance

9.3% moderate consensus consensus

Use of Flash Elements (or other plug-in content)

13% very minimal importance

10.1% moderate consensus consensus

Use of Advertising on the Page

11% very minimal importance

8.6% moderate consensus consensus

Use of Google AdSense (specifically) on the Page

8% very minimal importance

7.3% moderate consensus consensus

Comments on On-Page (Non-Keyword) Ranking Factors:

Russell Jones – If Google only ranked the “tried and true”, their results would be old and outdated. Recency is a valuable asset when links are hard to come by.

Tom Critchlow – Factors like recency (freshness) and content changes are difficult factors to pin down. A fresh page is a real asset if trying to rank for fresh queries and when QDF hits in but other times having an established page can be more of a benefit so sometimes you need one and sometimes you need the other.

Peter Meyers – Anecdotally, it feels like freshness is more important than ever. I’m amazed how often a blog post ranks within the first day, holding a top-10 position before finally settling a few spots (or even pages) lower.

Carlos Del Rio – HTML Validation is not necessary, but running validation is an easy way to catch broken code that can trap spiders. If you are not linking out at all you are sending a signal that you are not part of the Internet as a whole. Creating topical association is very important to maintaining a strong position.

Ian Lurie – Ratio of code to text and HTML Validation don’t have direct impacts, but by focusing on these factors you create semantically correct markup and fast-loading, content-rich pages, which has a huge impact. The description tag and static/non-static URLs won’t impact rankings. But they do impact click-through on your listing once you see it. So I’m not suggesting you ignore your description tag or use messy URLs. But when you change them, expect more clicks for the rankings you have, not better rankings.

Keyword-Focused Anchor Text from Internal Links

Location in Information Architecture of the Site (where the page sits in relation to the site’s structural hierarchy)

51% moderate importance

10.7% moderate consensus consensus

Internal Link Popularity (counting only links from other pages on the root domain)

51% moderate importance

9.1% moderate consensus consensus

Quantity & Quality of Nofollowed Links to the Page

25% minimal importance

10.8% moderate consensus consensus

Percent of Followed vs. Nofollowed Links that Point to the Page

17% very minimal importance

11.4% moderate consensus consensus

Comments on Page-Specific Link Popularity Ranking Factors:

Jon Myers – SEO ranking for me is won in the external factors today. It is the old 80%/20% rule and time needs to be invested in the getting your linkage right as this is where you will win. Make sure you are focusing the keyword anchor text and directing to the relevant pages. The focus has to be towards a quality and quantity mix and also don’t get all your links from one type of source, make sure you have a blend as this I believe counts well for you as well.

Use PR rank to determine high ranking links but make sure they are relevant is always a good starting point to refine the links and clean out the bad ones and refocus the anchor text on the good ones as I tend to find that more often than not about 85% of external links will have brand keywords as anchors, so you could be missing some great opportunities. Never forget though ones the bots are there make sure the internal linkage is good as it counts for a lot!

Todd Malicoat – Links are to SEO’s what Snowflakes are to Eskimos. Off page factors were the most significant change in search relevancy that lead Google to become the 800 lbs. gorilla that they are. Focus on this area, and understanding the difference between different links and their relationship to search result sets, and you will understand the crux of good SEO. Understand how to place a value on link equity of a site, and you have a very powerful skill in evaluating competition in a search result.

Jane Copland – I certainly don’t put much merit in the idea that the number of followed vs. nofollowed links pointing at a page plays a part in Google’s traditional web search results anymore. Think of all the really high-quality social links from sites like Twitter that carry nofollow tags: it would be completely ridiculous to regard a high number of nofollowed links as a detrimental trust metric.

Site-Wide Link-Based Ranking Factors

Trustworthiness of the Domain Based on Link Distance from Trusted Domains (e.g. TrustRank, Domain mozTrust, etc.)

66% very high importance

9.5% light consensus consensus

Global Link Popularity of the Domain Based on an Iterative Link Algorithm (e.g. PageRank on the domain graph, Domain mozRank, etc.)

64% high importance

11% light consensus consensus

Link Diversity of the Domain (based on number/variety of unique root domains linking to pages on this domain)

64% high importance

9.5% light consensus consensus

Links from Hubs/Authorities in a Given Topic-Specific Neighborhood (as per the “Hilltop” algorithm)

64% high importance

10.9% light consensus consensus

Temporal Growth/Shrinkage of Links to the Domain (the quantity/quality of links earned over time and the temporal distribution)

Percent of Followed vs. Nofollowed Links that Point to the Domain

21% very minimal importance

11% light consensus consensus

Comments on Site-Wide Link-Based Ranking Factors:

Carlos Del Rio – There’s likely to be a tipping point with Nofollowed links vs. Followed links to the domain where it’s not a factor unless the tipping point is reached where there are too many Nofollowed links. Then it has a Negative impact.

Will Critchlow – Temporal growth of links above and beyond the value of the links themselves tends to only have a positive impact on QDF-type queries in my experience.

Aidan Beanland – Google have stated in the past that .edu, .mil and .ac TLD extensions do not inherently pass any more value than others, but that alternative factors may make this seem to be the case.

Ann Smarty – Domain strength is a highly important factor (still). We keep seeing pages with 0 strength of their own hosted on reputable domains ranked very high for very competitive words.

Lisa D Myers – I do think the distance between trusted domains and you could have an impact, the bots are becoming more intelligent with their reading and will take associations of domains with them as they go to compare to the next site it links to. Using LSI (Latent Symantic Indexing) was just the start for the search engines, I belive the algorithm is now so much more sophisticated and has the power to read not only latent symantic between content on a page but between sites. My mind boggles when I think about the process, it’s a bit like when you were little and tried to imagine the end of the universe! Again it comes down to content, if you generate highly valuable and relevant content the brilliant links will come to you. I know, I know, it’s such a cliche, but unfortunately true. If links are the currency of the web, content is the bank!

Site-Wide (non-link based) Ranking Factors

Site Architecture of the Domain (whether intelligent, useful hierarchies are employed)

52% moderate importance

13% moderate contention consensus

Use of External Links to Reputable, Trustworthy Sites/Pages

37% low importance

10.8% moderate consensus consensus

Length of Domain Registration

37% low importance

14.3% moderate contention consensus

Domain Registration History (how long it’s been registered to the same party, number of times renewed, etc.)

36% low importance

12.3% moderate contention consensus

Server/Hosting Uptime

32% minimal importance

11.4% moderate consensus consensus

Hosting Information (what other domains are hosted on the server/c-block of IP addresses)

Use of Security Certificate on the Domain (for HTTPS transactions)

Citations/References of the Domain in Google Knol Articles (beyond the value of the link alone)

13% very minimal importance

9.2% moderate consensus consensus

Use of a Google Search Appliance on the Domain

6% very minimal importance

7.4% moderate consensus consensus

Use of Google AdSense on the Domain

5% very minimal importance

6.1% moderate consensus consensus

Use of Google AdWords for Ads Pointing to the Domain

5% very minimal importance

5.8% moderate consensus consensus

Alexa Rank of the Domain (independent of actual traffic)

5% very minimal importance

5.8% moderate consensus consensus

Compete.com Rank of the Domain (independent of actual traffic)

5% very minimal importance

6.1% moderate consensus consensus

Use of Google’s Hosted Web Apps (not App Engine) on the Domain

3% very minimal importance

4.9% strong consensus consensus

Comments on Site-Wide (non-link based) Ranking Factors:

Adam Audette – Many of these factors aren”t directly related to how Google will score a domain for ranking, BUT these all have a huge factor on the SEO of the site. For that reason it was slightly difficult to pull them out one by one. I believe DMOZ is still very juicy. Hint: Google still uses the directory. Double hint: search for “clothing” sometime and see what 2 of the top 10 results are. That’s significant, especially because there’s no ability to get a link on the ranking category page at DMOZ (which feeds Google’s). Citations/mentions/quality directories are certainly tracked and factored in, along with Google’s domain detective work. XML sitemaps can help with crawl fluidity but aren’t a scoring factor per se.

Marshall Simmonds – Search engines either don’t care to, are unable, or aren’t good at organic comprehensive crawls of large sites (those in the millions of pages) due to size and depth of content. This means it’s critical to the success of enterprise level sites to implement XML sitemaps whereas smaller sites may not see the benefit as much.

Wil Reynolds – Alexa and compete rankings would be of very little value given the prevalence of Google analytics and the Google toolbar. They can get much more accurate data from their own properties.

Richard Baxter – Recent changes to Domain Registration Ownership, especially if the domain has been allowed to expire, impact the results extremely negatively.

Ian Lurie – Use of Adsense/Google Apps/Google Search or other search engine-owned tools, though, won’t impact results at all. If your site is so hurting, SEO-wise, that you have to point an Adwords ad at it to get crawled, you’ve got bigger problems.

MySpace Data About the Domain or Page

Comments on Social Media/Social Graph Based Ranking Factors:

Hamlet Batista – Matt Cutts explained in a video that Google doesn’t care how many twitter followers you have. Their algorithms only care about the links.

Dan Thies – Put me down for “no way, never” on all these.

Todd Malicoat – Social bookmarking is a quality indicator. Brand mentions are a quality indicator. If I was a search engine engineer, I would likely rank brand mentions based on social media conversations from third parties that were easiest to derive valid data from.

Ian McAnerin – I’m inclined to believe that in this case "sometimes a link is just a link", to paraphrase Freud.

Usage Data Ranking Factors

Historical Click-Through Rate from Search Results to the Exact Page/URL

42% low importance

11.4% light consensus consensus

Historical Click-Through Rate from Search Results to Pages on this Domain

39% low importance

11.3% light consensus consensus

Search Queries for the Domain Name or Associated Brand

36% low importance

12.3% moderate contention consensus

Use of Query Refinement Post-Click on a Search Result

32% minimal importance

11.2% light consensus consensus

Average “Time on Page” Duration

26% minimal importance

12% light consensus consensus

Data from Google’s SearchWiki Voting, Ratings, Comments

19% very minimal importance

9.1% moderate consensus consensus

References/Links to the Domain in Gmail Emails

9% very minimal importance

7.7% moderate consensus consensus

Comments on Usage Data Ranking Factors:

Jessica Bowman – While usability are factors likely in the formula, I haven’t seen much to indicate this is impacting rankings - especially for larger authoritative websites. Companies do need to focus on these because they will likely become a bigger impact in the next year.

Andy Beal – While Google may well be experimenting with including these factors in their algorithm, I’ve seen no evidence to support wide-spread usage.

Adam Audette – CTR on a search result is a large cumulative factor, and brings in page load time as well, which is something we’re very focused on at present.

Carlos Del Rio – Brand and domain additives to search terms have become especially important since the Vince change.

Ian Lurie – None of these factors have a significant impact YET. But they’re coming on. If you think Google’s ignoring all that toolbar data and Searchwiki info, you’re mental.

Negative Ranking Factors

Cloaking with Malicious/Manipulative Intent

68% very high importance

10.7% light consensus consensus

Link Acquisition from Known Link Brokers/Sellers

56% high importance

13.1% moderate contention consensus

Links from the Page to Web Spam Sites/Pages

51% moderate importance

12.1% moderate contention consensus

Cloaking by User Agent

51% moderate importance

15.2% moderate contention consensus

Frequent Server Downtime & Site Inaccessibility

51% moderate importance

12.3% moderate contention consensus

Hiding Text with same/similar colored text/background

49% moderate importance

15.3% moderate contention consensus

Links from the Domain to Web Spam Sites/Pages

48% moderate importance

13.1% moderate contention consensus

Excessive Repetition of the Same Anchor Text in a High Percentage/Quantity of External Links to the Site/Page

46% moderate importance

11% light consensus consensus

Cloaking by IP Address

46% moderate importance

15.3% moderate contention consensus

Hiding Text with CSS by Offsetting the Pixel display outside the visible page area

Keyword Stuffing in the Meta Keywords Tag

Comments on Negative Ranking Factors:

Excessive Repetition of the Same Anchor Text in a High Percentage/Quantity of External Links to the Site/Page:

It would depend on how they are acquired for long-term benefit

If you create a WP theme with Buy Viagra in the footer, don’t expect to be flavor of the month with human reviewers

Hiding Text with CSS display:none; Styling:

Is it part of a navigation system that allows the user to eventually display the content?

If you hide a whole bunch of keywords, or keyword stuffed links, it could be a significant factor

Over-Optimization of Internal Link Anchor Text:

A perfectly optimized link points to content that is a perfect landing page for the keyword, and Google isn’t going to give you a penalty for something they expect you to do, tell the truth with your links.

Use of Keyword-Rich Anchor Text Internal Links in Footers:

With CSS you could have the header in the footer or the footer in the header

does 100+ links in that part of the visible page make sense for users?

Link Acquisition from Buying Old Domains & Redirecting:

If redirecting and hosting the old content on the new domain, this can be achieved successfully.

Debra Mastaler – A lot of the comments you hear about widgets/301’ing microsites/buying old domains etc affecting you negatively is a result of overblown scare tactics perpetuated by a handful of people. There are a lot of legitimate uses for these tactics and when done well and as part of an overall marketing plan, they are successful.

Tom Critchlow – A lot of these factors depend on intent. For example, cloaking by user agent can be fine so long as the intent is pure and many large sites get away with it and have done for years. Also, a fair number of the link factors (such as manipulative bait and switch campaigns) are more likely to have 0 value than negative value. We’ve seen Google preferring to de-value spammy techniques/links rather than apply penalties for them where possible.

Carlo Del Rio – I have yet to see a net negative from buying old domains, but it often doesn’t make any positive ranking either. Currently manipulative link acquisition is the biggest threat in causing negative results. Crossing repetitive anchor text and high velocity acquisition is like playing with matches—eventually you get burned.

Peter Meyers – It seems like the negative impact of link farms is very niche-specific. In some cases, Google really cracks down (real estate, for example), but in smaller niches I still see people running blatant link farms and getting away with it. I’m not sure the penalty has really made its way into the core algorithm.

Factors Negatively Affecting the Value of an External Link

Domain Banned from Google’s Index for Web Spam

70% very high importance

10.8% moderate consensus consensus

Domain’s Rankings Penalized in Google for Web Spam

65% very high importance

10.9% light consensus consensus

Link is Determined to be “Paid” Rather than Editorially Given

63% high importance

12.5% moderate contention consensus

Domain Contains Links to a Significant Amount of Web Spam

52% moderate importance

11.3% light consensus consensus

Domain Has Not Earned Trusted Links

41% low importance

11.8% light consensus consensus

Comments on Factors Negatively Affecting the Value of an External Link:

Adam Audette – All killers. The last one is a grey area...but a major factor. If a link is determined to be paid, it will normally be filtered out from the site’s link graph. But there are occasions when a serious penalty will occur from too many paid links.

Chris Bennet – I don’t know what measures Google has taken to algorithmically spot low quality paid/rented links but it would be very easy to build a tool that could spot 80-90% of the crap without breaking a sweat.

Hamlet Batista – Links from banned sites are pretty much worthless.

Todd Malicoat – Most links won’t hurt you, but if you put significant effort into obtaining a link that won’t help you, you’ve negatively impacted your bottom line. Make sure you are hunting for links that matter.

Ian McAnerin – Links are not a rankings factor – trust and topic are. Links just represent this. If you can show that the link has little/no trust or is unfocused, then it will not be worth much. If you can show it has neither trust nor accurately indicates the topic, then there is no reason to count it.

Geographic Location of Visitors to the Site (the country/region from which many/most visitors arrive)

Comments on Geo-Targeting Factors::

Joost de Valk – Ranking in different countries has different requirements. For some countries, f.i., Google cannot reliably determine server location based on IP, and some languages are so alike to Google’s algorithm that weird stuff sometimes happens (Dutch pages ranking in German results, f.i.)

Russell Jones – Any opportunity you have to tell Google explicitly what region for which your site is designed — do it. Make their job as easy as possible.

Wil Reynolds – The address associated with the registration of a domain wouldn’t make sense to have too large of an impact as this would severely hurt sites that are registered in one country yet have content for multiple countries on their site

Aidan Beanland – In my experience Google still relies mainly on the ccTLD, IP location of host and Webmaster Tools regional target. Secondary cues are given less importance than in other search engines.

Language of the site can act as an automatic geo-filter, as only queries in that language would match content from that country. However, this can (and does) cause confusion when the same language is spoken in multiple countries, or the same words are used across multiple languages.

Kristjan Mar Haukson – Address Associated with the registration of the domain we have worked with large companies with their address given in one country but targeting another and this has not played any role that we have seen.

Consensus Scale

Note: Consensus and contention percentages are calculated based on the standard deviations of contributor answers.

Link Building Survey

In addition to surveying the experts on ranking factors, we also asked about the effectiveness of a variety of link building tactics. Since link acquisition is such an important part of SEO, and links are so difficult to attain, we felt that discovering the value SEO experts found in their own campaigns (and those of their clients) would provide substantive return for this document. Below the tactics, we’ve included the ranking factors that affect the value derived from an external link to help you judge the efficacy of a specific pursuit (or the ROI from a link campaign).

Web Advertising (Banners, PPC, etc.)

Forum Link Building (Signatures, Link Drops, etc.)

Automated Blog, Guestbook and Open Form Comment Spam

10% very minimal value

8% light consensus consensus

Comments on Effectiveness of Link Building Tactics for SEO:

Jessica Bowman – One of the reasons that public relations (beyond press release publication) isn’t as effective as it could be is because public relations departments and agencies aren’t up to speed, bought into and committed to doing things differently to maximize opportunities for search engine rankings.

Adam Audette –

Some strategies we like:

Creating really high-quality content and promoting it to niche twitter profiles we’ve set up, thereby reaching bloggers in the niche.

Putting a paid ad program on Stumble and Reddit to gain momentum on a piece of content; then reaching out to the voters/savers directly and requesting a guest blog gig or feature post.

Contacting site owners, bloggers, etc and requesting a link to our valuable resource.

Wil Reynolds – I think niche directories and small generic directories are two different types of links. Niche directories give you topical authority, based on the link graph its telling Google its about a topic which inherently should make those links somewhat more valuable than a small generic directory about all kinds of topics.

Marcus Tandler – With regard to “Buying Old Domains and 301’ing Them” It’s limited to a number of domains. So one domain = good. 10 domains 301’d = not so good anymore. It’s also rather important, that the domain has been in the same niche. But most importantly, there’s gotta be an instance of the keyword on the target domain, that’s used in the anchortexts pointing to the domain (So if there’s 100 links with the anchor “seomoz” pointing to the old domain, you should also have an instance of the keyword “seomoz” on the domain you redirecting the domain too!).

Todd Malicoat – Lots of great techniques for link development. Understand how to place a value on a link, and evaluate a backlink profile, and you will understand which acquisition strategy for links will make the most sense for your individual site rankings and bottom line.

Factors Affecting the Value of an External Link

Global Authority/Importance of the Source Domain (based on iterative calculations of the site-wide link graph)

68% very high value

9% light consensus consensus

Keyword Anchor Text of the Link (matched against the query term)

67% very high value

8.4% light consensus consensus

Quantity of PageRank Passed by the Link (i.e. Passable PageRank assigned to the page ÷ number of links on the page)

59% high value

10.4% light consensus consensus

Position of the Link on the Page in Content (rather than sidebars, footers, etc.)

53% moderate value

10.5% light consensus consensus

Source Page’s Topical Relevance to the Link Target

53% moderate value

10.3% light consensus consensus

Position of the Link on the Page in Relation to Other Links (surrounded by many other links vs. alone inside non-linked content)

46% moderate value

10.0% light consensus consensus

Source Domain’s Topical Relevance to the Link Target

46% moderate value

10.6% light consensus consensus

Quality of Other External Links on the Page

42% low value

11.6% light consensus consensus

Comments on Factors Affecting the Value of an External Link:

Jon Myers – Trust and Quality is what links is all about. Make sure the sites you get links from are high PR and well trusted by Google and you will get great success. Key after sourcing is to get the anchor text focused and relevant and landing on the correct pages.

Russell Jones – The success of blog reviews as a link building technique indicates that in-context links are valuable. However, it would be incorrect to assume this is due to topical measurements. If this were the case, article syndication would still be viable. It is more likely that a link found within unique content is considered truly editorial.

Adam Audette – Contextual links, within content matched to the target page, is incredibly powerful. Anchor text is less important than the terms surrounding the link and keyword density of the page (or said differently, the topic of the page – what the page is about). Sidebar links and footer links are easy for Google to spot and often in the form of shingles that get filtered out anyway. However, they can be powerful advertising opportunities if done correctly and even a nofollowed link can send big traffic, which can in turn lead to links.

Roger Monti – High trust sites tend to have a stronger ranking effect than lesser domains. Position of the link is very important. A dream link is one near the top of the page wrapped in a headline tag or big fonts originating on a topically relevant high trust web page.

Lisa D Myers – A link within content of a page is far juicier than a link from a footer or sidebar, the relevancy of the content around the link, latent semantic indexing, is extensively used to determine the relevancy and power the link should be given. A link from a trusted site with highly relevant content to your site will always have more power.

Consensus Scale

Note: Consensus and contention percentages are calculated based on the standard deviations of contributor answers.

Additional SEO Data

The following individual questions were posed to our panel of experts and help provide insight into critical (and sometimes contentious) debates in the SEO field. The pie charts represent the percentages of respondents who gave that particular answer.

Broad algorithmic elements to Google’s rankings

24%

Trust/Authority of the Host Domain

22%

Link Popularity of the Specific Page

20%

Anchor Text of External Links to the Page

15%

On-Page Keyword Usage

7%

Visitor/Traffic & Click-Through Data

6%

Social Graph Metrics

5%

Registration & Hosting Data

Which of the following statements best describes your opinion/experience with Google’s “Brand/Vince” update from February of 2009?

51%

The algorithmic changes/update affected algorithmic factors that unintentionally (and non-universally) appeared to preference some SERPs towards well-known, public brands.

36%

Google is now showing a slightly stronger preference towards websites associated with well-known, public brands.

9%

Google is now showing a much stronger preference towards websites associated with well-known, public brands.

4%

No major shift occurred that preferences Google’s results towards well-known, public brands.

Which of the following best represents your opinion of how Google handles algorithmic evaluation of content on subdomains (excluding potential special cases such as Blogspot, Wordpress, etc.)?

83%

Content on Subdomains inherits some, but not all, of the query-independent ranking metrics of the root domain (or other subdomains) and is judged partially as a separate entity.

10%

Content on Subdomains never inherits all of the query-independent ranking metrics of the root domain (or other subdomains) and is judged largely as a separate entity.

7%

Content on subdomains inherits all or nearly all of the query-independent ranking metrics of the root domain (or other subdomains) and is judged much the same as other content on the shared root domain.

Note: Subdomains in this context refer to the 3rd-level domain name only, e.g. “sub.domain.com” while root domains refer to the 2nd-level domain name,e.g. “*.domain.com” including all subdomains.

To what extent do you believe Google Web Search employs data gathered from Google Analytics to influence their search rankings?

74%

Google Analytics data is used only in aggregate form to help with pattern identification and broad user behavior analysis.

16%

Google Analytics data is not used in any way.

6%

Google Analytics data is employed on a website by website basis and can positively or negatively affect a site's rankings.

4%

Google Analytics data is employed on a website by website basis, but can only impact search rankings consideration positively (no web spam or penalty analysis is conducted).

Which of the following statements most accurately represents your belief/experience about how 301 redirects are handled by Google?

70%

301’s pass a high percentage (but not 100%) of query dependent and independent ranking factors from one URL to another only when certain content & spam analysis algorithms are satisfactorily met.

23%

301’s universally pass a high percentage (but not 100%) of the query dependent and independent ranking factors from one URL to another.

7%

301’s universally pass 100% of the query dependent and independent ranking factors from one URL to another.

In your opinion/experience, do links from Wikipedia directly contribute positively to Google’s search engine rankings, despite the use of nofollow?

68%

Yes, but these citations are not treated directly as links, merely as indications of potential quality/authority/trustworthiness.

26%

No. Wikipedia links only appear to pass value because many other sites/pages scrape and re-publish the links without nofollows.

6%

Yes, the links are treated as though the nofollow didn’t exist

Which of the following statements best represents your opinion of how Google will treat links as part of their ranking algorithm over the next 5 years?

48%

Links will decline in importance, but remain powerful, as newer signals rise from usage data, social graph data & other sources to replace them.

37%

Links will continue to be a major part of Google’s ranking algorithm, but dramatic fluctuations will occur in how links are counted and which links matter.

15%

Links will continue to be a major part of Google’s ranking algorithm, much as they have been over the past 5 years.

0%

Links will become largely obsolete, much the way keyword stuffing fell by the wayside in the late 1990’s.

Contributors (A special thank you to all who contributed to the Ranking Factors Survey)